Patent Document 1 has disclosed a pilot on-off valve functioning as a refrigerant circuit switching device that is applied to a vapor compression type refrigeration cycle device and switches a refrigerant circuit. In the pilot on-off valve of Patent Document 1, refrigerant pressure in a pilot space (a space to which refrigerant pressure biasing a main on-off valve in a valve closing direction is applied) is changed by the operation of a pilot valve, so that the main on-off valve is opened and closed.
If the main on-off valve is opened when a pressure difference between refrigerant pressure on the upstream side of the main on-off valve and refrigerant pressure on the downstream side of the main on-off valve (hereinafter, referred to as differential pressure between the front and rear sides of the main on-off valve) is large in this kind of pilot on-off valve, a refrigerant flows from a high-pressure side of the cycle to a low-pressure side of the cycle at a burst. For this reason, a large amount of refrigerant passing noise is generated.
Accordingly, the pilot on-off valve of Patent Document 1 reduces a refrigerant passing noise by being adapted to gradually discharge a refrigerant, which is present in the pilot space, through a capillary tube or the like so that the main on-off valve is gradually opened, when the main on-off valve is opened.